Tranquilizing composition comprising 2-ethyl-cis-crotonylurea



United States Patent TRAN QUILIZIN G COMPOSITION COMPRISING Z-ETHYL-CIS-CROTONYLUREA Ofis E. Fancher, Elkhart, Ind., assignor to Miles Laboratories, Inc., Elkhart, Ind., a corporation of Indiana No Drawing. Application June 6, 1956 Serial No. 589,594

6 Claims. (Cl. 167-65) This invention relates to a new article of manufacture and to methods of compounding and using the same. More particularly, the invention relates to the highermelting isomer of 2-ethylcrotonylurea in dosage unit form having utility in the alleviation of nervous tension and anxiety in human beings. This application is a continuation-in-part of my application Serial No. 316,812, filed October 24, 1952, now abandoned.

As is well known, sedatives of the barbiturate class in common use today have certain detrimental properties making them inherently dangerous. In the first place, these compounds generally have a narrow range between effective and dangerous doses. In addition, their use is very commonly followed by a dull or depressed feeling, or hangover, after their sedative effect has passed. Finally, it is now believed that sedatives of the barbiturate group are capable of producing some degree of addiction.

It is an object of the invention to provide a sedative composition which is not habit forming, which is effective to produce sedation over an extremely wide dosage range before a toxic dose is reached, and which is substantially free of the untoward side-effects which characterize many sedatives of the prior art. A further object is to provide a method of producing sedation in human beings through the internal administration of the compositions of the invention. The term sedation as used in the specification includes what is commonly referred to in the art as tranquilization.

A sedative, according to the invention, includes as an essential ingredient the higher-melting isomer of 2-ethylcrotonylurea (2-ethyl-cis-crotonylurea), which compound is preferably combined with appropriate pharmaceutical fillers, carriers, extenders, and/ or excipients to render the composition particularly suitable for human use.

The isomers of Z-ethylcrotonylurea can be prepared by procedures indicated in the following equations.

OHzCHa Ag O CHgCH -C-CONHCONI-Iz CHaOHz-C-CONHCONH; l 3r 11-0-011 CHzOHs CHaCHzC-C ONHO N112 OHgGHz-C-CONHCONH:

l 3r C r -H The Z-ethyl-cis-crotonylurea used in this invention is obtained in the reaction using silver oxide, and melts at 192193 C. The isomer obtained in the reaction using pyridine is Z-ethyl-trans-crotonylurea, and melts at 157- 158 C.

The 2-ethyl-cis-crotonylurea is best prepared according to the following method;

Fifty-four gm. of carbromal (2-bromo-2-ethylbutyrylurea) in 600 cc. of isopropanol was stirred and refluxed Pyridine for three hours with 27.8 gm. of anhydrous silver oxide. The reaction mixture was filtered and the silver residue was extracted with cc. of boiling isopropanol. The filtered and dried solids which separated weighed 22.5 gm. and melted at 189-1905". Concentration of the filtrate yielded an additional 3.3 gm. of product which melted at -170. These two crops were separately obtained as white needles by crystallization from alcohol and exhibited slight solubility in water. The first crop gave 21.7 gm. of Z-ethyl-cis-crotonylurea with a melting point of 19l193 C., and the second crop gave 0.9 gm. with a melting point of l91193 C. for a total yield of 42.4 gm. or 63 percent of the theoretical.

In accordance with the invention, the active ingredient Z-ethyl-cis-crotonylurea may be associated with a pharmaceutical carrier, diluent or the like which may be either a solid material or, when the composition is intended for oral administration in liquid form, a suspending liquid, such as glycerine. Thus, the compositions may take the form of tablets, powders, capsules, suspensions or other dosage forms which are particularly useful for oral ingestion. More specifically, the present compositions in the preferred solid form, may be prepared by mixing the 2- ethyl-cis-crotonylurea with solid diluents and/or tableting adjuvants such as cellulose powder, cornstarch, lactose, talc, stearic acid, magnesium stearate, gums, or, indeed, any tableting materials used in pharmaceutical practice which are not incompatible with the Z-ethyl-cis-crotonylurea.

An important characteristic of Z-ethyl-cis-crotonylurea is its low toxicity when compared with that of other sedatives, such as the barbiturates. This quality has been well demonstrated by an extensive series of tests on rats, which tests have shown 2-ethyl-cis-crotonylurea to have an LD of 2500 mgm., as against 160 mgm. for phenobarbital, 55 mgm. for pentobarbital, and 50 mgm. for secobarbital.

A further remarkable, and quite unexpected, characteristic of 2-ethyl-cis-crotonylurea is the extremely wide oral dosage range within which sedation may be secured with absolute safety. Thus, it has been shown that with 2-ethyl-cis-croto-nylurea, sedation in rats is secured over the entire range between about 1% and about 60% of the LD at increased doses of 2-ethyl-cis-crotonylurea above 60% of the LD the rats progress deeper into a subhypnotic state but do not reach the true hypnotic state until the dose reaches about 95% of the LD By way of comparison, the barbiturates mentioned above have very narrow oral dosage ranges for producing sedation in rats, commencing variously from about 3 to about 10% of the LD and extending to a point just short of 20% of the LD In the case of phenobarbital, the true hypnotic state is reached with doses of about 45% of the LD while with pentobarbital and secobarbital, true hypnosis is reached at about 30% of the LD Similar effects have been shown in comparative tests of these sedatives on dogs. It is seen, then, that 2-ethyl-ciscrotonylurea is many times less toxic than many of the commonly used barbiturates, and that it produces sedation at smaller fractions of the toxic dose and offers a much larger dosage range than that offered by the barbiturates before more profound effects are encountered.

The outstanding sedative properties of 2 ethyl-ciscrotonylurea described above, have been found applicable 1 LDso refers to the dose which is lethal for 50% of the animals of the particular species tested.

to human beings in the alleviation of nervous tension and anxiety. Of particular importance is the fact that the undesirable side-etfects, such as hangover or depression, which commonly result from the use of prior-art sedatives, are substantially avoided by the use of 2-ethyl-cis-crotonylurea.

As noted above, sedative compositions according to my invention may take any of a variety of forms, and vari- JLIS carriers, adjuvants, diluents, and filters, may be em- :tloyed therein. The percentage of active ingredient in ny compositions may be varied, although it is advisable hat the proportion of active ingredient be such that the :ompositions provide a suitable human dose.

Although 2-ethyl-cis-crotonylurea is insoluble in water, .t is readily absorbed by the body after oral administraion. The effective clinical dose for adults ranges from me to six grains (two to four grains being efiective in nost cases) taken one to four times daily, or as conlitions demand. For chldren, the dosage is correspondngly smaller, according to the age and weight of the :hild. In a preferred form of administration, tablets are impaired containing the drug in a quantity between one 1nd six grains. In preparing such tablets the drug is preferably compounded with one or more of the aforenentioned carriers, adjuvants, fillers, etc., and the tablets nay be finally coated with sugar or other coating ma- :erials in accordance with common practice in the tablet nanufacturing art. Of course, a larger tablet scored to permit its being broken into the aforementioned dosage mits, or a number of smaller tablets adapted to be :aken at the same time to constitute a dosage unit, are also satisfactory.

The following examples are illustrative of procedures which may be employed in the preparation of two forms 3f sedative compositions in accordance with the invention.

Example I Z-ethyl-cis-crotonylurea 300 parts. Cellulose powder 25 parts. Dicalcium phosphate 66 parts. Methyl cellulose 10 parts dissolved in 150 parts of water. Corn starch 50 parts. Magnesium stearate 1 part.

The 2-ethy1-cis-crotonylurea, cellulose powder and dicalcium phosphate are thoroughly mixed in the dry state, after which the methyl cellulose solution is intimately mixed with the mixture. The wet mixture is sifted through a #10 screen and thereafter dried in a warm air oven. The dried mixture is then sifted through a #14 screen, blended with the corn starch and magnesium stearate, and the final blended mixture pressed into scored or unscored tablets of the desired size. A tablet of this composition weighting 450 mgm. will contain 300 mgm. of 2-ethyl-cis-crotonylurea.

4 Example ll 2-ethyl-cis-crotonylurea grams 24 Glycerine do 48 Carboxymethylcellulose do 1 1 Aluminum magnesium silicate do 13 Sugar do 340 Preservative (methyl parahydroxybenzoic acid) grams 0.5 Preservative (butyl parahydroxybenzoic acid) grams 0.2 Water ml 2000 The 2-ethyl-cis-crotonylurea and glycerine are milled together to form a paste. The carboxymethylcellulose and aluminum magnesium silicate are dissolved in part of the water, and the sugar is dissolved in the remainder of the water. The two syrups thus formed are then mixed With the 2-ethyl-cis-crotonylurea paste, the preservatives added, and the mixture stirred for one-half hour, after which it is homogenized. The suspension thus produced contains 60 mgm. (about 1 grain) of 2-ethyl-ciscrotonylurea per 5 ml. (1 teaspoonful).

I claim:

1. An article of manufacture comprising a quantity of from about one to six grains of 2-ethyl-cis-crotonylurea and a pharmaceutical carrier in dosage unit form.

2. An article of manufacture comprising a quantity ranging from about one to six grains of 2-ethyl-ciscrotonylurea in a pharmaceutical capsule.

3. A composition of matter comprising a quantity of from about one to six grains of 2-ethyl-cis-crotonylurea and an effective amount of a non-toxic pharmaceutical binding agent pressed together in a dosage unit form.

4. A medicinal agent for the alleviation of nervous tension and anxiety comprising about one to six grains of 2-ethyl-cis-crotonylurea in dosage unit form.

5. A capsule for alleviation of nervous tension and anxiety, said capsule containing a solid diluent with an amount of from about one to six grains of Z-ethyl-ciscrotonylurea.

6. The method of inducing transquilization in human beings comprising administering internally to a human being, in dosage unit form, between about one and about six grains of Z-ethyl-cis-crotonylurea.

Rice. I. A. P. A., vol. 33, Sept. 1944, pp. 289-297 (p. 293 pert.). 

6. THE METHOD OF INDUCING TRANSQUILIZATION IN HUMAN BEINGS COMPRISING ADMINISTERING INTERNALLY TO A HUMAN BEING, IN DOSAGE UNIT FORM, BETWEEN ABOUT ONE AND ABOUT SIX GRAINS OF 2-ETHYL-CIS-CROTONYLUREA. 